Explanatory phrase for the drinking of 'Off License' bought alcohol (often large in cans, hence the term) outside of licensed venues such as pubs, bars, night clubs, venues etc.
Practice often undertaken due to lack of funds or overpriced alcohol in said venues.
"Shall we go in and get a drink?"
"Nah boy, I'm skint... let's do streetcan"
"Ok"
"Great"
